In 1976, the concept of entity-relationship diagramming and data modeling was developed. Data entities and data entity relationships are the major components of prior art entity-relationship diagrams. One function of data models is to design database structures such as database tables, database table columns, and database table indexes.
Data entity relationships are the only prior art data relationships recognized by this methodology. These data entity relationships are used to link data entities together to form designed data access paths between the resultant instantiated database tables. These data access paths are used to join data from two or more database tables to form a coherent set of extended data records. These data entity relationships of data models and their associated database instantiated data access paths are essential to the fundamental function of all relational databases.